Pedro Clar Rossello defeated Guillermo Olaso 7-6 6-1 in the Spain F19 round of 32 on hard. The upset overturned the form book — Guillermo Olaso came in leading the head-to-head 4–0. Pedro Clar Rossello claimed a first win over Guillermo Olaso in five meetings, narrowing the head-to-head to 4–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2012-02-06 | Spain F1 | F | clay | Guillermo Olaso | 2-6 6-3 6-3 |
| 2011-01-31 | Spain F4 | SF | clay | Guillermo Olaso | 6-7(2) 6-1 6-4 |
| 2010-10-25 | Spain F38 | SF | clay | Guillermo Olaso | 1-6 6-3 6-2 |
| 2007-11-19 | Spain F42 | R32 | clay | Guillermo Olaso | 7-6(2) 6-2 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.